Portal - RenderMan

Space transformations
void transformThroughPortal(
point pCur;
string portalSpace1; string portalSpace2;
output point pPortal1; output point pPortal2; output point pCurNew
)
{
pPortal1 = transform( "current", portalSpace1, pCur );
pPortal2 = rotate( pPortal1, PI, point( 0, 0, 0 ), point( 0, 1, 0 ) );
pCurNew = transform( portalSpace2, "current", pPortal2 );
}
void vtransformThroughPortal( ... ) { ... }
void ntransformThroughPortal( ... ) { ... }